Rich writes:

Bruce wrote in
:

David Dyer-Bennet wrote:
Robert Coe writes:
On Thu, 12 Apr 2012 06:27:36 -0700, "Mr. Strat"
wrote:
: Does anyone care about Sigma? Their cameras have always sucked
: ass. Only idiots and cheapskates buy their products.

I've had pretty good luck with several Sigma lenses (carefully
avoiding any that have a bad reputation or whose zoom ranges
challenge common sense). But I can't imagine buying one of their
cameras.

Well, I *am* a cheapskate.

The Sigma 12-24 full-frame has no competitor (at least, nothing that
reaches the extreme of 12mm). I got mine for $800 or some such. It's
been very handy to have (I lost my wide-angle when I went full-frame,
my Tokina 12-24 DX).

The Sigma 120-400 got a bunch of better reviews than the Nikon 80-400
when I bought it, and again was $800 or some such (I believe one was
$750 and one was $850 but I forget which was which) compared to (then)
$1300 for the Nikon.


Sigma lenses get far better reviews than they deserve because the
review samples are carefully hand-assembled with particular attention
paid to centering the lens elements.

They are therefore unrepresentative of the Sigma lenses sold to
real-world buyers which suffer from many flaws of which decentered
lens elements is the second most frequent (and serious) after
mechanical build quality. You don't get what you don't pay for.

It is almost impossible to find a Sigma lens from a store that
performs as well as one reviewed in a magazine. The fact that the
lenses are then sometimes offered to reviewers at extremely attractive
prices (not unadjacent to $0.00) is an added incentive to write a
favourable review. The promise of ongoing advertising revenue for the
publication helps seal the deal.


That is the key, the advertising $ potential is the hold back, rather
than being supplied lenses at good prices, except perhaps for very
expensive lenses. They could easily buy a lens from a store, review it,
sell it second hand. If the thing included decentering, they could use
that in the review, along with Sigma's response when they complained
about it.
Another problem with review sites, even those run by amateurs with money
is they need the products too soon. So they have to have access to the
manufacturers which means they are beholding to them.

Yes, to actually do a competent job they need to obtain *multiple*
samples through *normal retail channels*. Consumer Reports knows how to
do this, and takes the time / expense, even with things as expensive as
cars.

It's absolutely true that the consistency from lens to lens is one of
the important attributes of "quality" manufacturing. And examining one
sample tells you nothing about this; one hand-tuned sample tells you
less than nothing.

I take reviews based on a single sample, as is typicl of photo gear, to
represent the best possible performance that could be hoped for in a
product.
--
David Dyer-Bennet, ; http://dd-b.net/
Snapshots: http://dd-b.net/dd-b/SnapshotAlbum/data/
Photos: http://dd-b.net/photography/gallery/
Dragaera: http://dragaera.info